A Mossy Wall

We had to change our shift pattern by an hour last night and it threw all of us. What with that and the hail storms and trying to get all my paperwork ready I missed out on my dark-time walk. By the time we finished work the sky was full of heavy clouds that threw both rain and hail earthwards, so I only ventured as far as the local shop and got soaked, but spotted this damp, mossy wall on the way.